Evaluation of Composite Pavement Joints Using the Falling Weight Deflectometer

Abstract

Many concrete pavements have been overlaid to preserve roadway systems. As these composite pavements become in need of rehabilitation, appropriate evaluation of these structures is important in selecting rehabilitation options, planning maintenance, and estimating quantities for bidding purposes. Falling weight deflectometer (FWD) testing was carried out in this study to examine the effect of geophone layouts on joints evaluation in terms of load transfer efficiency (LTE), peak deflections, and differential deflections. Furthermore, FWD testing was carried out on composite pavements prior to and following milling of asphalt overlay on an arterial section to quantify the influence of asphalt overlays on measured deflections on the loaded and unloaded sides of joints as well as their influence on computed differential deflections, LTEs, and locating potential voids. The study found that the geophones layout suggested by the long-term pavement performance manual for joint testing provides the more critical loading condition and is recommended for use. Moreover, load-based correction factors were suggested to mitigate the impact asphalt overlays have on deflection measurements and considerably improve the evaluation of concrete joints in composite structures.